This study examined 100 consecutive patients who presented at neurological unit with headache of recent onset (described as headache that "appeared for the first time ever in the last 12 months. Patients with past history of headache were excluded except, if a change of character of the previous headache had been the reason for the referral.") Every patient was examined by a physician and given a CT scan with and without intravenous contrast. Some of the patients were given lumbar puncture, blood tests, MRI, and magnetic resonance angiography, if needed.
90% of the patients had headaches for the first time, while 10% had previous—but now different—headaches.
The study reported that the neurological examination was normal in 80% of the patients. Further investigations, however, turned up some very serious conditions: Intracranial neoplasm (21%); subacute meningitis (5%); intracranial hematoma (3%); and hydrocephalus (2%). In all, "Headaches were considered organic in 39 (39%) of the 100 patients, and in 21 (26%) of the 80 with normal neurological examination."
"It has been suggested that with recent-onset headache, a CT or MRI should be obtained if the headache is severe or occurs with nausea, vomiting or abnormal signs. However, headache in four patients with intracranial tumors in our study was mild, no nausea or vomiting occurred, and was not aggravated by Valsalva nor did it awake them during the night, and were unassociated with abnormal neurological signs."
"We suggest that neuroimaging studies should be performed in all adult patients with non-vascular headache of recent-onset, and no previous history, irrespective of the characteristics of the headache..."
Duarte J, Sempere AP, Delgado JA, et al. Headache of recent onset in adults: a prospective population-based study. Acta Neurologica Scandinavica 1996;94:67-70.